Metal briquette compacting method and machine therefor



June 17,1969 a McDONALD 3,450,529

METAL BRIQUETTE COMPACTING METHOD AND MACHINE THEREFOR Filed March 19,1968 INVENT OR WARD D. MucDONALD W. H wfw ATTORNEY United States PatentUS. Cl. 75211 9 Claims ABSTRACT OF THE DISCLOSURE This disclosuresrelates to a process and apparatus for making metal briquettes forfoundry operations. The briquettes are made, for example, from oilymetal particles, such as metal turnings, which are fed to a furnace toburn the oil therefrom. In the furnace, the particles are heated to ahigh temperature of, for example, 1200 to 1400 F. The heated andde-oiled particles are passed directly to a hopper which feeds thebriquetting mechanism. The temperature of the de-oiled particles aresensed and is maintained within a predetermined range for briquetting byadjusting the feed to the furnace in accordance with the sensedtemperature. The amount of de-oiled particles in the feed hopper iscontrolled to prevent overflow of the feed hopper and to maintain thedensity of the briquettes by sensing the level of de-oiled particles inthe feed hopper and adjusting the speed of the briquetting rollsaccordingly to maintain the proper level.

This invention relates to processing of metallic particulate materials.In one of its aspects it relates to a sintering operation for compactingde-oiled metal particles, such as turnings, into briquettes where thede-oiled particles are fed at a high temperature to a hopper and passedfrom the hopper through briquetting rolls, wherein the level ofparticles in the hopper is sensed and the speed of the briquetting rollsis adjusted accordingly to maintain the level of particles within thehopper such that the particles do not overflow the hopper and such thatsuflicient particles are present in the hopper to adequately feed thebriquetting rolls to make high density metal briquettes.

In another of its aspects, the invention relates to a sinteringoperation wherein oily metallic particles are fed to a de-oiling zone,the particles are heated to a de-oiling temperature in the presence ofoxygen, and are then fed directly to a briquetting zone wherein theparticles are compacted to high density briquettes, wherein thetemperature of the de-oiled particles is sensed between the de-oilingzone and the briquetting zone, and the amount of oily particles fed tothe de-oiling zone is adjusted to maintain the temperature of thede-oiled particles suitable for hot briquetting.

In still another of its aspects, the invention relates to an apparatusfor compacting de-oiled metallic particles such as turnings comprising:compacting rolls which form metallic briquettes when particulatemetallic material is fed between the rolls as they turn, a feed hoppermeans aligned with the rolls to feed hot de-oiled turnings between therolls for compacting, means to rotate the compacting rolls, and means tovary the speed of the rolls so that the amount of de-oiled metallicparticulate material in the hopper can be maintained at a predeterminedlevel, such that suflicient material is fed to the rolls to produce adense briquette and so that the amount of hot particulate material inthe feed hopper will be insuflicient to overflow the hopper.

In still another of its aspects, the invention relates to a de-oilingapparatus wherein oily metallic material is passed to a de-oiling meanswhich is adapted to burn the oil from the metallic material whileheating the metallic material to a high temperature, means are providedto sense the temperature of the de-oiled material passing from thede-oiling means, and means are provided to regulate the amount of oilymaterial fed to the de-oiling means in accordance with the sensedtemperature such that the temperature of the metallic effluent from thedeoiling means is maintained within a predetermined tem perature range.

Murphy, in Iron Age, June 22, 1967, pp. 65-67, discloses a new processfor making dense metal briquettes wherein oily iron borings are heatedin a de-oiling furnace and passed directly to compacting rolls.

One requirement of this process is that the temperature of the heatedmetallic material fed to the rolls must be in the range of 1000 to 1400F., preferably in the range of 1200 to 1400 F. De-oiling furnaces usingan excess of oxygen and in some cases fuel, generally produce hotde-oiled metallic material in the range of 1200 to 1400 F. However, theoil content of the charge varies, and therefore, the temperature of thede-oiled borings passing out of the de-oiling furnace will fluctuate.Sometimes, the temperature of the eflluent boring from the de-oilingfurnace will exceed 1400 F. and in some cases be less than 1000 F.

I have now discovered that the temperature of metallic material fed tothe compacting rolls can be controlled by sensing the temperature of thede-oiled borings as they pass from the de-oiling furnace and, according,adjusting the speed of the material to the furnace to maintain thetemperature within the predetermined range.

When the briquetting rolls are fed from the eflluent from the de-oilingfurnace, the hopper load tends to fluctuate due to the varying amountsof de-oiled material fed to the compacting rolls. When the hopper getstoo full, the de-oiling furnace must be shut down to prevent the hopperfrom overflowing and in some cases to prevent sintering or fusingtogether of the de-oiled borings in the feed hopper. When the level ofde-oiled borings becomes too low, for example, below about 500 lbs., thedensity of the briquettes drops appreciably.

I have now discovered that the density of the briquettes can bemaintained at a high level without overflow or sintering in the hopperby sensing the level of metallic material in the hopper and,accordingly, adjusting the speed of the rolls to maintain the properrange of material within the hopper.

By various aspects of this invention one or more of the following, orother, objects can be obtained.

It is an object of this invention to provide an improved process andapparatus for producing high density metallic briquettes.

It is a further object of this invention to provide an integratedprocess and apparatus for producing high density metal briquettes fromoily metal borings wherein variation in temperature of feed to thebriquetting rolls is minimized.

It is a further object of this invention to provide a method andapparatus for producing high density metal briquettes wherein overflowof and sintering in the feed hopper to the compacting rolls iseliminated.

It is yet another object of this invention to provide a process andapparatus for producing high density metal briquettes wherein thepropensity to produce low density metal briquettes due to littlemetallic material in the feed hopper is eliminated.

Other aspects, objects, and the several advantages of this invention areapparent to one skilled in the art from a study of this disclosure, thedrawings, and the appended claims.

According to the invention, there is provided an operation forcompacting de-oiled metal particles wherein deoiled particles such asiron turnings and borings are fed to a feed hopper and passed from thehopper through compacting rolls. The level of the hot metal materialwithin the feed hopper is sensed and the speed of the compacting rollsis adjusted accordingly to maintain the level within the feed hopper ata predetermined range such that sufficient turnings are maintained inthe hopper to adequately feed the briquetting rolls for making highdensity briquettes and to eliminate overflow of the material in the feedhopper.

Further according to the invention, the compacting rolls are fed by theeffluent from a de-oiling furnace in which the temperature of theeffluent from a de-oiling furnace is sensed and the amount of materialfed to the de-oiling furnace is controlled so as to maintain thetemperature of the de-oiled turnings Within a range suitable forbriquetting.

With the operation of the manual controls can be employed for adjustingthe speed of the compacting rolls responsive to the level of material inthe hopper or the speed of the rolls can be adjusted manually.

Similarly, the control of the feeder device for the deoiling furnace canbe done automatically or manually responsive to the sensed temperatureof the de-oiled turnings.

The invention will now be described with reference to the accompanyingdrawing in which a schematic embodiment of the invention is shown.

Referring now to the drawing, oily iron turnings or borings 2 are loadedinto hopper 4 for processing. The oily iron turnings pass from the lowerportion of the hopper 4 onto a conveyor 6 driven by motor 7, and arepassed to a bucket conveyor 8 driven by a motor 9. The oily ironturnings in the bucket conveyor are dumped into a feed trough 10 throughwhich the turnings pass to a rotary de-oiling furnace 12. The de-oilingfurnace 12 is of conventional design and is described more fully in myUS. Patent Nos. 2,852,418 and 2,925,821. In the deoiling furnace, theiron turnings are heated in the presence of oxygen to a temperature ofabout l200 to 1300 F.

After the turnings have been de-oiled, they pass from the exit end ofrotary furnace 12 onto chute 14 and into feed hopper 16.

The de-oiled turnings 26 pass from feed hopper 16 through throat 18 andthen through briquetting rolls 20 which compress and compact thede-oiled turnings into briquettes 28. Each roll 20 has a plurality ofpockets which are aligned with pockets on the adjacent roll so thatde-oiled turnings falling between the rolls 20 will be compacted in thepockets to form briquettes. A screen vibratory conveyor 22 latches thebriquettes and immediately passes them into a quench tank containingwater 32. The elapse of time between the removal of the briquettes 28from the briquetting rolls 20 and the quenching in the water tankpreferably is the range of 30 seconds to 2 minutes.

A small percentage of the turnings passing through the briquetting rollsare not pressed into briquettes. These turnings will drop through thescreen vibratory conveyor 22 onto a collector 24 and will be directed bya chute 34 to a suitable conveyor 36 to be recycled to the vibratoryconveyor 6.

For a proper briquetting operation, the de-oiled turnings must have atemperature of 1200 to 1300 F. The de-oiling process in the rotaryfurnace generally heats the turnings during the de-oiling process sothat the turnings at the exit end of the furnace are at a temperature inthe range of 1500 F. depending on the amount of oil on the originalturnings and the amount of turnings fed into the furnace. According toone embodiment of the invention, the temperature of the turnings at theexit end invention, automatic or of the furnace 12 is maintained atabout 1200 to 1300 F. by sensing the temperature at the exit end of thefurnace and controlling the speed at which the oily turnings are fed tothe furnace to maintain the predetermined temperature. To this end, atemperature sensing probe 38 senses the temperature of the de-oiledturnings as they leave the furnace 12 and transmits this information toa temperature recorder controller 40 which, in turn, controls a speedcontroller 42 for motor 7. Accordingly, if the temperature of thede-oiled turnings coming out of the furnace 12 is too high, thetemperature recorder controller 40 will cause speed controller 42 toreduce the speed of motor 7 to cause fewer oily turnings to be fed tofurnace 12. Conversely, if the temperature of the deoiled turnings istoo low, the temperature recorder controller 40 will cause the speedcontroller 42 to speed motor 9 to increase the amount of de-oiledturnings fed to the rotary furnace 12.

According to another embodiment of the invention, the de-oiled turnings26 are maintained at a predetermined level in throat 18 of the feedhopper 16. The deoiled turnings are at a temperature in the range of1200 to 1300 F. as they pass from the rotary furnace 12. If too many ofthese de-oiled turnings at 1200 to 1300 F. accumulate in the feed hopper16, the de-oiling operation will have to be stopped to prevent overflowof the turnings in the feed hopper 16 conversely if insufficientde-oiled turnings are in the throat 18 an insufficient amount of theseturnings will be passed to briquetting rolls 20 and the resultingbriquettes will have a low density.

To this end, a probe 44 and a probe 46 are provided at different levelsof throat 18 of feed hopper 16. These probes are used to indicate thelevel of turnings within the feed hopper 18. Suitable probes includeBindicator probes manufactured by the Bindicator Co. of Detroit. Thelevel of turnings in throat 18 of feed hopper 16 is maintained at apredetermined level, or between certain predetermined points in the feedhopper, by sensing the level of the de-oiled turnings 26 in throat 18and, accordingly, controlling the speed at which the briquetting rollsare turned. Thus, if the level of de-oiled turnings 26 in throat 18rises to or above probe 44, the speed of the briquetting rolls will beincreased so as to decrease this level of de-oiled turnings. Conversely,in the event that the level of de-oiled turnings within the throat 18falls to or below probe 46, the speed at which the briquetting rolls 20are turned will be reduced to increase the level within the throat.

To this end, a level controller 48 can be attached to probe 44 and 46.The level controller can control the speed controller 50 attached tomotor 21 which drives the briquetting rolls 20.

Thus the invention involves, in a more specific embodiment, maintainingthe temperature of the de-oiled iron turnings in the feed hopper atabout 1200" to 1300 F. and maintaining the level within throat 18 at apredetermined level to, on the one hand, maintain at least a minimumvalue for the density of the briquettes and, on the other hand, toprevent the de-oiled turnings from sintering and fusing together withinthe feed hopper.

The metallic materials can be compacted to make briquettes or similarcompressed articles from such materials as iron and steel turnings,copper, aluminum turnings and other particulate metallic material. Asused throughout this specification, the term briquette is intended tosignify all forms of compressed metal such as sheets, rectangles, etc.,as well as the well-known cylindrical shape.

The process and apparatus is especially suitable for compactingparticulate iron materials such as results from oily iron borings andturnings.

Generally, for iron borings, the weight of the borings in the feedhopper above the rolls will be at least 500 lbs.

Reasonable variation and modification are possible within the scope ofthe foregoing disclosure, the drawings, and the appended claims withoutdeparting from the spirit of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In a sintering operation for compacting de-oiled metal particles atelevated temperatures into high density briquettes wherein feeding meansare provided to feed the de-oiled particles to a compacting means, theimprovement which comprises sensing the amount of the de-oiled particlesin said feeding means being fed to said compacting means, and adjustingthe speed of said compacting means to maintain a predetermined amount ofparticles being fed to said compacting means such that said particles donot overflow said feeding means and such that sufficient amount ofparticles are maintained in said feeding means to adequately feed saidcompacting means to make high density briquettes.

2. A sintering operation according to claim 1 wherein said metalparticles are iron turnings and the temperature of said de-oiledturnings are in the range of 1000 to 1400 F.

3. A sintering operation according to claim 2 wherein said feeding meansis a feed hopper and the weight of said metallic particles in saidhopper above said compacting means is at least 500 lbs.

4. A sintering operation according to claim 1 wherein said feeding meansreceives said particles as the effluent from a de-oiling zone.

5. A sintering operation according to claim 4 wherein said de-oiledmetallic particles are heated to a temperature in the range of 1200 to1400 F. in said de-oiling zone.

6. In a sintering operation wherein oily metallic particles are fed to adc-oiling zone, said oily metallic particles are heated to a de-oilingtemperature in the presence of oxygen to burn oil from said metallicparticles, the hot de-oiled metallic particles are passed to a hotbriquetting zone wherein said hot de-oiled metallic particles arecompacted to high density articles, the improvement which comprises:sensing the temperature of said de-oiled turnings between said de-oilingzone and said briquetting zone and adjusting the speed of said oilymetallic particles to said de-oiling zone to maintain the temperature ofsaid de-oiled metallic particles at a suitable temperature for saidcompacting step.

7. A sintering operation according to claim 6 wherein said de-oiledmetallic particles are iron borings and are maintained in the range of1000 to 1400 F.

8. A sintering operation according to claim 6 wherein said de-oiledmetallic particles are iron borings and the temperature of said de-oiledmetallic particles is maintained in the range of 1200 to 1400 F.

9. A sintering operation according to claim 6 wherein said de-oiledmetallic particles are passed from said deoiling zone to a hopper priorto passing to' said briquetting zone, the level of said de-oiledmetallic particles in said hopper is sensed and the rate at which saidde-oiled metallic particles are compacted is adjusted to maintain thelevel in said hopper such that said metallic particles do not overflowsaid hopper, and to maintain the level such that sufiicient de-oiledmetallic particles are present so that a high density sintered productis produced.

References Cited UNITED STATES PATENTS 2,814,564 11/1957 Hayden 752113,298,060 1/1967 Michalak 18-9 3,328,843 7/1967 Murphy 189 X 3,366,7171/1968 Rohaus 264--40 BENJAMIN R. PADGETT, Primary Examiner.

ARTHUR I. STEINER, Assistant Examiner.

US. Cl. X.R.

